Millions of Americans are facing dangerous heat and humidity going into the July Fourth holiday as a major heat wave spreads across large parts of the central and eastern United States.

For many people, this is the time of year for cookouts, beach trips and other outdoor activities. Soccer fans are packing into stadiums for World Cup matches. But summer also brings the risk of dangerously high temperatures in many parts of America.

Cities as far north as Chicago and Detroit experienced a heat index over 100 degrees Fahrenheit (37.8 Celsius) in early July, and large parts of the East Coast, including New York and Washington, D.C., were bracing for similar conditions on Independence Day. Washington, D.C., and Philadelphia both canceled Independence Day parades and shortened or delayed outdoor gatherings, including the Great American State Fair on the National Mall, because of the extraordinary heat risk.

Map shows the heat risk forecast with extreme heat in large parts of the Midwest and Mid-Atlantic region and at least major heat in the rest of the West.
The NOAA Weather Prediction Center’s heat forecast, released July 1, 2026, shows the maximum heat risks states can expect to see at some point through Sunday, July 5. NOAA Weather Prediction Center

I study health risks in a warming climate as a professor of public health, and I’ve seen heat become a growing concern. In the U.S., hundreds of people succumb to heat-related illnesses each year. Older adults and people in areas that historically haven’t needed air conditioning tend to see the highest rates of illnesses during heat waves, as Chicago saw in 1995 when at least 700 people died in a heat wave.

Here are some of the key warning signs to watch for when temperatures rise – and ways to keep cool when the heat and humidity get too high.

Heat-related deaths in the US

Heat-related illnesses occur across a spectrum, and mild heat stress can quickly progress to life-threatening heat stroke if a person is exposed to dangerous conditions for too long.

Mild forms of heat-related illness include heat cramps and heat rash, both of which can be caused by extensive sweating during hot conditions. Cooling the body and drinking cool fluids can help.

When heat-related illnesses progress into heat exhaustion, the situation is more serious. Heat exhaustion includes symptoms such as dizziness, nausea, excessive sweating, feeling weak, thirst and getting a headache.

A construction worker sits and puts his head down, still in the hot sun.
Construction workers are often out in the heat for long periods of time, including during this heat wave in Los Angeles in July 2024. Etienne Laurent/AFP via Getty Images

Heat exhaustion is a signal that the body is losing its ability to maintain a stable core temperature. Immediate action such as moving to a cool, ideally air-conditioned space, drinking liquids, loosening clothes and applying wet cloths are some of the recommended steps that can help keep heat exhaustion from progressing to the most dangerous form of heat-related illness, heat stroke.

Heat stroke is a medical emergency. At this point, the body can no longer maintain a stable core temperature. A body with heat stroke can reach 106 degrees Fahrenheit or higher rapidly, and that heat can quickly damage the brain, heart and kidneys.

An illustration showing symptoms associated with heat exhaustion, such as dizziness, heavy sweating, nausea and weakness; and with heat stroke, including confusion, dizziness and passing out.
Signs of heat exhaustion and heat stroke, from the National Weather Service and Centers for Disease Control and Prevention. NOAA/CDC

Typically, someone suffering heat stroke has exhausted their reserves of sweat and salt to stay cool, so sweating eventually stops during heat stroke. Their cognitive ability fails, and they cannot remove themselves from danger. Heat stroke can cause seizures or put someone into a coma as their core temperature rises. If the condition is not treated immediately, and the core temperature continues to rise, heat stroke becomes fatal.

Because heat exhaustion can lead to heat stroke, addressing heat-related illnesses before they progress is vital.

How to tell when the heat is too high

Heat risk isn’t just about temperature – humidity also increases the risk of heat-related illnesses because it affects how well sweating will cool the human body when it gets hot.

Instead of just looking at temperature when planning outdoor activities, check the heat index, which accounts for heat illness risk associated with temperature and relative humidity.

It doesn’t take very high temperatures or very high humidity for the heat index to enter dangerous territory.

A chart shows how humidity and temperature combine for dangerous conditions. For example, 86 degrees F at 80% humidity is a heat index of 100. 94 degrees at 45% humidity is also a heat index of 100.
A heat index chart shows how heat and humidity combine for dangerous conditions. NOAA

However, the heat index is still a conservative measure of the impact of heat on humans, particularly for outdoor workers and athletes at summer practices. This is because temperature measurements used in weather forecasting are taken in the shade and are not exposed to direct sunlight. If someone is outside and exposed to the direct sun, the actual heat index can be as much as 15 F higher than the heat index chart indicates.

A more sophisticated measurement of heat effects on human health is what’s known as the wet-bulb globe temperature, which takes into account other variables, such as wind speed and cloud cover. Neither takes into account a person’s physical exertion, which also raises their body temperature, whether working at a construction site or playing soccer.

Tips for staying safe in a heat wave

How can you stay cool when heat waves set in? The answer depends in part on where you are, but the main points are the same:

  • Avoid strenuous outdoor activities in high temperatures if possible. If you start to feel symptoms of heat-related illnesses, drink fluids that will hydrate you. Find shade, rest, and use cool, damp cloths to lower your body temperature. If you see signs of heat stroke in someone else, call for medical help.
  • Be careful with fans. Fans can be useful if the temperature isn’t too high because they wick sweat away from the body and induce evaporative cooling. But at very high temperatures, they can accelerate heat buildup in the body and lead to dangerous conditions. If indoor temperatures reaches 95 degrees or higher, using fans can actually be dangerous and raise the risk of heat-related illnesses.
  • Find a cooling center, library or community center where you can get inside and rest in an air-conditioned space in the hottest hours. In places such as Phoenix, where high temperatures are a regular hazard, cooling centers are typically opened in summer. Northern cities are also opening cooling centers as heat waves occur there more frequently than they did in the past. Urban areas with a lot of pavement and buildings – known as heat islands – can have temperatures well above the city’s average.
  • Hydrate, hydrate, hydrate! Drink plenty of fluids, and don’t forget about the importance of electrolytes. Heat-related dehydration can occur when people sweat excessively, losing water and necessary salts from the body. Some sports drinks or rehydration fluids restore electrolytes and hydration levels.

Older adults and people with disabilities often face higher risks from heat waves, particularly if they can’t easily move to a cooler environment. Communities and neighbors can help protect vulnerable populations by providing cooling centers and bottled water and making regular wellness checks during high heat.

Summer can be a season of fun. Just remember the risks, keep an eye on your friends and neighbors when temperatures rise, and plan ahead so you can beat the heat.

This article originally appeared on The Conversation. You can read it here.

  • New Russian research suggests that the human lifespan could be up to 156 years
    Photo credit: CanvaResearchers found what's preventing us from living longer.
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    New Russian research suggests that the human lifespan could be up to 156 years

    Humans can live much longer if certain barriers are addressed.

    According to the Guinness Book of World Records, the oldest person lived to the ripe age of 122 years old. Such a lifespan is an incredible feat, but what if the average person could beat that record by 34 years? Recent research done in Russia has led scientists to believe that the average human lifespan could be up to 156 years.

    The researchers at Skoltech Biomed Technologies Center developed a mathematical model that allowed them to “switch on” a variety of aging mechanisms. This allowed them to calculate a human’s lifespan where mortality risk never increased with age. After experimenting with different scenarios and conditions, they found the biggest barriers to longevity were caused by non-renewable tissues and somatic mutations.

    What are these barriers against longer life?

    Somatic mutations are DNA changes within a cell. They accumulate over time during a human’s life and cannot be reversed with any existing therapy. These DNA errors that pile up in our cells contribute to the aging process.

    Many human organs like the liver and skin continually replace cells and regrow damaged portions of themselves. However, there are two organs that can’t do this: the brain and the heart. Brain tissue (neurons) and heart tissue (cardiomyocytes) cannot regenerate. This proves to be the most prominent biological limit that shortens our lifespans. This explains why issues like dementia and heart disease are prominent causes of death and morbidity later in life. Since those organs’ tissues don’t replace damaged cells, they’re prone to irrevocably decline over time.

    “The key finding of the study is the discovery of substantial differences between tissue types. Neurons and cardiomyocytes, which lack the ability to divide, turned out to be the main limiting factors: when all other causes of aging are eliminated, somatic mutations alone reduce the theoretical median lifespan from 1,759 years (for a hypothetical non-aging human organism) to 156 years,” said Evgeny Efimov, a research intern at the Skoltech Biomed Technologies Center, researcher at AIRI, and one of the key authors of the study.

    This suggests that somatic mutations and DNA damage is what ultimately prevents humans from living indefinitely, even if our brains and hearts regenerated cells like other organs.

    So what’s next?

    Now knowing these biological limitations, the researchers hope to study other areas of aging impacting the human lifespan that could plausibly be reversed. This includes mitochondrial dysfunction, telomere shortening, epigenetic drift, and loss of proteostasis. 

    The hope is to have a clearer priority list of issues for future therapies to tackle. This is not just to possibly extend life, but to improve lives in general. By developing a fully comprehensive theory of aging, Skoltech hopes to pinpoint which aspects of aging are within our scope to address. After all, thoroughly studying each puzzle piece that makes up human life gives us a better understanding of the whole.

    Of course, other impactful factors in a person’s lifespan can be addressed today. As most know, things like diet, sleep, and exercise are among them. A person’s living environment can also negatively impact their lifespan if it doesn’t have clean air, access to clean water, and so on.

    For now, the best method for living long is to follow instructions from your physician. Whether you make it to 156 years or not, living well is best for whatever time you’re given.

  • Screen time guidelines for kids and adolescents have shifted as research paints a more nuanced picture
    Photo credit: PeopleImages/iStock via Getty ImagesWhat kids are doing on tablets seems to matter more than how long they use them.

    Concerns surrounding young people’s screen time are widespread.

    Australia became the first country to ban social media for users under 16 in December 2025, and DenmarkFrance and the U.K. have since announced similar restrictions to begin this year.

    In the U.S., as of mid-2026, more than 30 states have passed laws banning or restricting cellphones in K–12 classrooms; in 2023, the U.S. surgeon general issued a formal advisory on social media and children’s and adolescents’ mental health; and bestselling books tell parents that smartphones are “rewiring” their children’s brains.

    These concerns and policies are part of a quickly changing national and international conversation around how young people spend time on screens and its relationship to their overall health and development. My reading of the mounting research on this issue across disciplines is that the popular narrative blaming screens and smartphones for an adolescent mental health crisis runs well ahead of the current evidence.

    I study adolescent digital media use and its influence on social, emotional and academic outcomes. A growing body of research suggests that one-size-fits-all solutions are not the answer and that managing appropriate use of digital media needs to take into account a child’s developmental milestones, how parents and adults around them use media, and the ways kids use it to connect and learn with friends and family.

    Screen time: From monolith to multifaceted

    Wide adoption of digital media and the internet broadened the range of experiences young people could have online. At the same time, the digital age introduced newfound uncertainties. As with the advent of radio, comic books and arcades, adults worried about how children might interact with or be affected by internet use.

    In response, the American Academy of Pediatrics first recommended in 1999 that parents and caregivers keep children under 2 away from screens. In the decades since, professional guidance largely treated children’s media use as a behavior to be mitigated.

    Policies introduced by the academy in 2013 and 2016 continued to advise that school-age kids and adolescents – those ages 5 to 18 – be restricted to no more than two hours of “entertainment” screen time a day. The goal was to curb risks associated with heavy media use, among them disrupted sleep, online safety, cyberbullying and physical inactivity.

    Originally created for young people’s engagement with stationary media that tend to be confined to one room or context – for example, watching television – these hourly limits became outdated with the integration of smartphones and other digital devices into everyday life. Compared with watching television, online media was far more difficult to track and define, and more nuanced in its use.

    Developmentally beneficial activities such as educationsocializing and leisure have come to rely on the internet to extend and maintain face-to-face connections. Remote schooling and social distancing during the COVID-19 pandemic only accelerated this digitization of daily life.

    In my view, adopting strict time limits and restrictions could pose risks to children’s well-beingautonomy and development, for example, by harming adolescent self-esteem.

    The latest guidelines

    In January 2026, the American Academy of Pediatrics retired its decade-old framework that had largely organized its advice around hourly screen limits. The new policy statement on children, adolescents and digital media diverges from this blanket approach. Instead, it suggests parents consider the larger picture in which this media use exists rather than lumping all screen use together.

    Similar to the World Health Organization’s 2019 guidance for children under 5, the American Academy of Pediatrics still advises that parents avoid screen media for children younger than 18 months. This recommendation is largely because extended use by children by themselves can be problematic for many young children, crowding out important developmental milestones.

    Both the World Health Organization and the American Academy of Pediatrics also recommend that when children under 24 months use screens, they should be limited to content and devices that encourage children and caregivers to interact. For ages 2 to 5, screen time – including TV and interactive apps on devices – may be extended to more solo use, provided it’s high-quality digital media designed around learning goals in mathematics and reading. But recreational use should be limited to roughly an hour per day.

    For school-age children and teens, the newest guidance has begun to step away from fixed screen time limits and asks families to weigh online activity in the context of everyday life.

    Doing so recognizes that a child’s digital experiences are shaped by diverse factors rather than the hours spent online. Current guidelines call on caregivers to distinguish among types of media, from television and social media to video games and interacting with artificial intelligence chatbots. They also call for taking into account a child’s individual characteristics, such as their interests and personality, family members’ own use of screens, and the type of content children are spending time on.

    Rethinking screen time

    Moving beyond strict screen time limits includes questioning the kind of digital activities kids and adolescents participate in. Do the activities encourage time spent interacting with others online, which can help young people develop important skills and competencies?

    Scrolling an algorithm-based, auto-playing video feed likely does not equate to the same opportunities as video-chatting with friends, creating digital art or working with teammates in a multiplayer game. Research suggests these different uses relate to development in different ways and can help kids develop varying skill sets pertaining to everyday life and schooling.

    Indeed, a large review of current research found that young people who take part in a range of digital activities, such as browsing the web, online gaming or interacting on social media, show positive associations with social connection, identity exploration, civic participation and learning.

    A woman and two small children look at tablet screen
    Parental involvement in young children’s screen time has developmental benefits. Cultura Creative/Tetra images via Getty Images

    Using these guidelines at home

    The current evidence suggests parents and caregivers are best positioned to be digital instructors. Cutting children off altogether can carry its own risks for social and emotional development. Caregiver mediation of children’s screen time can produce widely different outcomes and effects, depending on whether the guidance is supportive or controlling.

    Considering your own digital media use is the first step: Are family members engaging in problematic or heavy media use that children in the household might emulate? What applications and uses are most common in the family, and what positive or negative effects might they have, depending on the child’s age? How could these digital activities be safely integrated with other everyday experiences to increase their benefit for children? Conversely, what online time might be better spent on face-to-face experiences?

    The American Academy of Pediatrics’ Family Media Plan tool turns these ideas into concrete questions. For example, it recommends working out what each child needs from digital technology, what activities screens might be crowding out, and where their family or household can build in screen-free time. The recommendation is to talk with each child about why they are drawn to particular apps or online activities, what they encounter while browsing, and what might be lost when kids bring phones to gatherings such as mealtimes.

    The debate over young people’s screen time is not going away. But the most up-to-date guidelines, and the growing body of research behind them, make a strong case for a more holistic approach. The guidelines treat digital media as a complex, diverse and evolving environment that children need to learn to navigate in the digital age. The risks and rewards depend, as with any developmental setting, on the child, the content and what online time might be crowding out.

    This article originally appeared on The Conversation. You can read it here.

  • ER doctor and mom sets the record straight for parents of kids with e-bikes and e-scooters
    Photo credit: CanvaA boy rides an e-scooter, left, while a girl is examined in an emergency room.

    An emergency room doctor and fellow mom has been noticing a troubling trend: Many parents are giving their kids something more powerful than bicycles to get around the neighborhood. As a result, she’s seeing more children come into the ER with injuries sustained in e-bike and e-scooter crashes. She recently went online with a plea to parents and young riders.

    Dr. Meghan Elizabeth Beach Martin, known online as Dr. Beachgem, posted a video in her scrubs discussing her concerns after seeing so many children come into the hospital with e-bike injuries during the summer months. She’s worried that too many kids and parents don’t understand the proper safety precautions. As a mother herself, she even questions why children are allowed to ride these devices at all.

    In the video, the doctor explains that some e-bikes can reach speeds of up to 28 mph. She says that if an e-bike goes any faster than that, it’s technically classified as a motorcycle. At those speeds, she regularly sees children with traumatic injuries and broken bones after hitting bumps, cracks in the road, or other vehicles. Many of them aren’t wearing helmets or protective pads, and some are even riding barefoot, making their injuries even more severe. Martin’s video has gained traction on Reddit and elsewhere online.

    E-bikes and e-scooters, examined

    Martin isn’t the only professional seeing a growing problem. The American College of Surgeons reports that there are more than 20,000 e-bike-related injuries each year. Meanwhile, a University of California, San Francisco study found that e-bike injuries doubled annually from 2017 to 2022. The same study found that e-scooter injuries increased by 45% each year during the same period.

    Before riding an e-bike, it’s important to follow proper safety procedures. Make sure you and your child understand your area’s laws regarding e-bikes, including any minimum age requirements. Always wear a helmet and other protective gear when riding. Consider choosing an e-bike with safety features such as motor-interrupt brake levers and disc brakes. These are just a few of the many safety tips experts recommend.

    The U.S. Consumer Product Safety Commission has similar safety tips for e-scooter riders. Wearing a helmet is one of its top recommendations, along with taking other basic precautions. The agency also recommends checking the brakes before riding and slowing down for bumps, cracks, and other road hazards.

    The vast majority of e-scooters and e-bikes are designed for only one rider, so avoid doubling up. Although laws vary by state and locality, wearing more protective gear is always the safer choice. Riders should also review local e-bike and e-scooter laws to make sure they are operating the vehicles safely and legally.

    A little research goes a long way toward making sure you and your children can ride safely. It’s also important for parents to understand that many e-bikes and e-scooters can travel at speeds that make them very different from a traditional bicycle. The last thing you want is for you or your child to become another emergency room statistic.

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